public async Task <bool> IsInVariantAsync(int experimentId, int userId, bool recordParticipation = true)
{
var experiment = await _experimentRepository.GetExperimentAsync(experimentId);
if (!experiment.IsActive)
{
return(false);
}
var user = await _userRepository.GetUserAsync(userId);
// Do some bit fiddling to make sure we always return the same value
// Use experiment.SplitType to calculate it based on the userId or the teamId
int differentiator;
switch (experiment.SplitType)
{
case GroupSplitType.User:
differentiator = user.UserId;
break;
case GroupSplitType.Team:
differentiator = user.TeamId;
break;
case GroupSplitType.None:
default:
throw new ArgumentOutOfRangeException();
}
var hash = GetParticipationHash(experiment.ExperimentId, differentiator);
var variant = (int)(hash % experiment.Variants.Length);
if (recordParticipation)
{
await _experimentRepository.RecordParticipationAsync(experimentId, userId, variant);
}
// 0 is always control
return(variant > 0);
}